Twin flow turbine housing

ABSTRACT

A twin flow turbine housing for two intake channels ( 13   a   , 14   a ) separated from one another in terms of fluid technology and intended for a fluid which is to be fed under pressure to a turbine, for example of a turbocharger, consists of two substantially symmetrical half-shells ( 13, 14 ) which between them enclose a substantially flat partition ( 18 ).  
     The two half-shells ( 13, 14 ) and the partition ( 18 ) consist of sheet metal and are welded to one another.  
     The outer contours of the half-shells have bent-over edges ( 20, 20 ′) and notches ( 30 ′) which are engaged by extensions ( 30 ) of the partition ( 18 ), the extensions ( 30 ) projecting outwards through the notches ( 30 ′) to enable them, after assembly of the half-shells, to be welded to the edges thereof. This manufacturing technology can be used for uncontrolled turbochargers and also for turbochargers controlled by a bypass.

FIELD OF THE INVENTION

The present invention relates to a twin flow turbine housing according to the precharacterizing clause of Claim 1.

BACKGROUND TO THE INVENTION

It is known that turbine housings of various kinds can be used for turbines, such as, for example, the turbine part of a turbocharger for motor vehicles.

In a conventional manner, typically used turbine housings are those which are made of cast iron and which have a spiral intake space for the combustion gases which are fed from the engine via a manifold to the turbine part of a turbocharger, from where they are then fed, for example through an annular gap which may contain a mechanism for varying the flow geometry, to the turbine wheel.

The spiral intake space surrounds the actual turbine space and, together with it, forms the turbine housing in which the turbine wheel and the mechanism for varying the geometry are housed.

It has already been proposed to make the turbine housing from sheet metal, advantageously in a double-walled design, in order on the one hand to save weight but especially, and more importantly, to prevent excessive cooling of the exhaust gases of the engine in the case of a cold turbocharger, since the downstream catalyst has to be heated as rapidly as possible to the operating temperature by the exhaust gases in order to achieve its full effect.

Part of the prior art, especially in the case of more powerful engines, is the provision of two spiral intake channels to the turbocharger, in particular for separating cylinder groups whose valve opening characteristics do not correspond.

It has also been proposed to use a single turbine housing for these two intake channel of a turbocharger which act in parallel, the two spiral intake spaces being arranged, so to speak, axially relative to one another, and the exhaust gases being fed either downstream to a single turbine wheel of relatively large turbochargers or to two different turbine wheels of two smaller turbochargers acting in parallel, but no solution has been proposed to date as to how such a twin turbine housing can be produced by a simpler method than casting from a lighter material than cast iron, for example sheet iron.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to produce a twin turbine housing with acceptable effort and at acceptable costs from sheet metal.

This object is achieved, according to the invention, by the features mentioned in the characterizing clause of Claim 1.

A twin flow turbine housing corresponding to the present invention may have half-shells which consist of sheet metal.

A twin flow turbine housing corresponding to the present invention may furthermore have a partition comprising sheet metal.

In a twin flow turbine housing corresponding to the present invention, the two half-shells and optionally the partition may be welded to one another.

In a twin flow turbine housing corresponding to the present invention, the partition and the half-shells may have outer contours adapted to one another.

In a twin flow turbine housing corresponding to the present invention, the outer contours of the half-shells may have notches, and the outer contour of the partition may have extensions, which, when the half-shells are assembled with the partition, come to lie in the notches and are welded to one another in this state.

In a twin flow turbine housing corresponding to the present invention, the outer contours of the half-shells may have bend-over edges which lie in the separation plane and are welded to one another.

In a twin flow turbine housing corresponding to the present invention, the half-shells may have circular inner contours on which are formed bent-over edges which lie in the separation plane and, like the outer contours, can be connected by means of notches and extensions and welding.

In a twin flow turbine housing corresponding to the present invention, the two intake channels may have bypass orifices leading to a bypass pipe, and this bypass pipe is divided into two part-bypasses by an extension of the partition.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail with reference to drawings, of which:

FIG. 1 shows a conventional cast iron twin flow turbine housing in perspective view,

FIG. 2 shows a twin flow turbine housing according to the invention, in the same view,

FIG. 3 shows a section parallel to the axis of a housing according to FIG. 2, and

FIG. 4 shows a section perpendicular to the axis according to FIG. 2.

DETAILED DESCRIPTION

FIG. 1 shows a conventional twin flow turbine housing for a turbocharger. Such twin housings are used in relatively powerful engines and serve for separating the exhaust gases of one group of cylinders from the exhaust gases of another group of cylinders.

In a four-stroke engine, it is known that a cylinder can have a plurality of valves and that these valves are subject to a specific opening and closing cycle controlled, for example, by the camshaft, different exhaust valves of the same cylinder opening at different times in order to allow gases to flow out under different pressure.

In the case of multicylinder engines, there will therefore be phases in which, for example, a high-pressure exhaust valve of a cylinder is open at the same time as a low-pressure exhaust valve of another cylinder, both valves releasing exhaust gases into the same manifold to the turbocharger. The result of this is that gases of the high-pressure exhaust valve may flow back into the cylinder whose low-pressure exhaust valve is open at the same time, something which must be avoided.

FIG. 1 is a computer drawing of a known modern twin flow turbine housing 1 for the two separate intake channels 2 and 3 to a single turbine wheel which is not shown, which corresponds, as has been explained above, to an embodiment of turbochargers for more powerful engines.

The entire housing is made of cast iron, and clearly evident are the two spiral intake channels 2 and 3, which have outer contours 2′ and 3′ completely separated from one another up to the gap 1′, and of course also separate, exhaust gas-carrying interiors, which lead radially to the single annular gap 1′ and thereby to one and the same turbine wheel which lies radially inside the annular gap 1′ and is not shown. Such a housing is relatively complicated simply from the point of view of the casting process and, also with respect to its weight, is by no means optimally adapted to present-day requirements for fuel efficiency, nor to the abovementioned requirement for optimum catalysis of the exhaust gases. The housing according to FIG. 1 also contains a bypass which can be closed by means of a valve 19.

FIG. 2, on the other hand, shows a twin flow turbine housing (the term “twin” relates to the presence of two intake channels) in which, viewed from the outside, only a single intake channel appears to be present, but in reality, as shown in FIGS. 2 and 3, the intake channel of this housing is divided by a partition 18 into two axially adjacent parts 13 a and 14 a, so that two intake channels completely separated from one another operationally thus form.

The twin turbine housing of FIG. 2 consists of a double-walled structure, the division into two separate intake channels relating only to the inner housing. The outer housing consists of two parts 12 and 15, which are connected to one another at 21. The inner housing consists of two half-shells 13 and 14 whose outer edges 20 and 20′ are bent over parallel to the separation surface A (cf. FIG. 3) and can thus be welded to one another.

The housing of FIG. 2 furthermore has two connecting flanges 11 and 16 for connection to the catalytic converter and to the central housing of the turbocharger.

Prior to welding, however, a partition 18 is placed between the two half-shells 13 and 14, this partition having an outer contour 18′ which corresponds to the outer contours 13′ and 14′ of the two half-shells 13 and 14, which outer contours are congruent to one another.

Corresponding notches 30′ are made in the outer contours 13′ and 14′ of the half-shells 13 and 14 so that, on assembly of the half-shells 13 and 14, and of the partition 18 located between them, dovetail-like extensions 30 of the outer contour 18′ of the partition 18 come to rest in the notches 30′, and, after assembly of these three parts, first the two half-shells in the region of the bent-over edge regions 20 and 20′ and then the dovetail-like extensions 30 of the partition, which project outwards through the half-shells, can be welded to those edges 20, 20′ of the half-shells which have already been welded to one another.

This gives a rigid sheet metal structure consisting of two channels which each correspond to the spaces 13 a and 14 a between the half-shell 13 or 14 and the partition 18, and which are adjacent in the region of the partition.

As shown in FIG. 4, the half-shells 13 and 14 do of course also have bent-over edge regions 31 along their inner contours, which form a circle within which the turbine wheel, which is not shown, comes to rest. In the vicinity of the circular edge regions 31 of the half-shells 13 and 14, notches and extensions can of course likewise have been formed, as in the outer regions.

As furthermore shown in FIG. 2, orifices 17 and 17′, which together complete a circle and which are provided for branching of bypasses, are provided on the half-shells 13 and 14, these orifices leading to a bypass line 22 which is formed by a pipe 17″ welded to the orifices 17, 17′ and which can be closed by means of a flap valve 19, by means of a lever 23 controllable from outside the housing.

The partition 18 has an extension 18′ which projects into the bypass line and follows this up to the seat of the valve 19. For this purpose, the bypass pipe 17″ can likewise consist of two half-shells, and the extension 18′ of the partition 18 may have further extensions 13 which engage, and are welded, in notches of bent-over, axial edges of the half-shells of the pipe 17″.

The invention has been described here in more detail above with reference to a working example, but a large number of possibilities are conceivable for permanently joining the two half-shells of the twin turbine housing and the partition located between them, without departing from or exceeding the scope of the present invention. 

1. A twin flow turbine housing (1) comprising two intake channels (13 a, 14 a) separated in terms of fluid technology and adapted for a fluid under pressure which is to be fed to a turbine wheel, wherein the twin flow turbine housing (1) is formed from two half-shells (13, 14) which are substantially symmetrical relative to one another and between them enclose a partition (18).
 2. The twin flow turbine housing according to claim 1, wherein the two half-shells (13, 24) comprise sheet metal.
 3. The twin flow turbine housing according to claim 1, wherein the partition (18) comprises sheet metal.
 4. The twin flow turbine housing according to claim 1, wherein the two half-shells (13, 14) and optionally the partition (18) are welded to one another.
 5. The twin flow turbine housing according to claim 1, wherein the partition (18) and the half-shells (13, 14) have outer contours (13′, 14′, 18′) adapted to one another.
 6. The twin flow turbine housing according to claim 5, wherein the outer contours (13′, 14′) of the half-shells have notches (30′), and the outer contour (18′) of the partition (18) has extensions (30) which, on assembly of the half-shells with the partition, come to rest in the notches (30′) and are welded to one another in this state.
 7. The twin flow turbine housing according to claim 1, wherein the outer contours (13′, 14′) of the half-shells have bent-over edges (20, 20′) which lie in the separation plane (A) and are welded to one another.
 8. The twin flow turbine housing according to claim 1, wherein the half-shells have circular inner contours on which bent-over edges (31) lying in the separation plane (A) are formed, which edges can be connected in the same way as the outer contours by means of notches (30) and extensions (30) and welding.
 9. The twin flow turbine housing according to claim 1, wherein the two intake channels (13 a, 14 a) have bypass orifices (17, 17′) leading to a bypass line (22), and in that this bypass line (22) is divided into two part-bypasses by an extension (18′) of the partition (18). 